[perl #7840] Hash Behaviour differs v5.6.0 to v5.6.1

From: "Michael G Schwern via RT" <perlbug-followup@perl.org>
Message-ID: <rt-3.0.11-7840-117401.4.81505529800216@perl.org>

(with minor tweaks)

p4raw-id: //depot/perl@25149

1 files changed, 20 insertions, 3 deletions

diff --git a/pod/perlop.pod b/pod/perlop.pod
index 04e1b48036..f7ff074533 100644
--- a/pod/perlop.pod
+++ b/pod/perlop.pod
@@ -689,13 +689,30 @@ both its arguments into the list.
 
 The C<< => >> operator is a synonym for the comma, but forces any word
 (consisting entirely of word characters) to its left to be interpreted
-as a string (as of 5.001).  If the argument on the left is not a word,
-it is first interpreted as an expression, and then the string value of
-that is used.
+as a string (as of 5.001).  This includes words that might otherwise be
+considered a constant or function call.
+
+    use constant FOO => "something";
+
+    my %h = ( FOO => 23 );
+
+is equivalent to:
+
+    my %h = ("FOO", 23);
+
+It is I<NOT>:
+
+    my %h = ("something", 23);
+
+If the argument on the left is not a word, it is first interpreted as
+an expression, and then the string value of that is used.
 
 The C<< => >> operator is helpful in documenting the correspondence
 between keys and values in hashes, and other paired elements in lists.
 
+        %hash = ( $key => $value );
+        login( $username => $password );
+
 =head2 List Operators (Rightward)
 
 On the right side of a list operator, it has very low precedence,